This invention relates to self-locking, adjustable pliers wrenches.
The art is sated with various self-locking adjustable pliers wrenches for gripping and locking onto objects within a rather wide size range. The innovations in such pliers are marked largely by improvements to the toggle mechanisms that permit the jaws to not only accommodate differently sized objects but also to lock onto the objects with varying degrees of force. Existing toggle mechanisms employ an adjustment component for use in adjusting the distance between the jaws so that they can grip and lock onto differently sized objects. The jaws must be pre-adjusted so that they can engage and grip an object, regardless of the size. As a result, existing self-locking adjustable pliers wrenches cannot be used with only one hand in the sequential gripping of differently sized objects, because a pre-adjustment of the jaws is required from the gripping of one object to the gripping of another differently sized object.
This required pre-adjustment of the jaws in the sequential gripping of differently sized objects is a significant deficiency in the art and it is clear that a adjustable wrench that could be employed for sequentially gripping differently sized objects with a selected gripping force without having to be sequentially pre-adjusted would mark a significant improvement over the prior art. The present invention achieves this and provides artisans with an adjustable pliers wrench that is easy to construct and easy to employ with only one hand for sequentially gripping differently sized objects without the need for sequentially pre-adjusting the jaws.
The above problems and others are at least partially solved and the above purposes and others realized in an improved self-locking, adjustable pliers wrench including a fixture having a handle and an opposing stationary jaw, a co-acting jaw pivoted to the fixture and a lever pivoted to the co-acting jaw and movable between opened and closed positions. Disposed between the handle and the lever is a toggle assembly. The jaws are movable between opened and closed conditions in response to movement of the lever between its opened and closed positions. The architecture of the toggle assembly permits the jaws to accommodate differently sized work pieces and causes the jaws to lock against a work piece positioned there between in the closed position of the lever.
The toggle assembly includes a guide, a locking element, a cam, an arm and an adjustment element. The guide is attached proximate the handle and the locking element is arranged on the guide for reciprocal and canting movements. At least one attached biasing element urges the locking element toward the stationary jaw. The arm is pivoted to the lever. The cam is disposed angularly relative to the guide, and is pivoted to the arm and to the locking element so as to be movable in response to movement of the lever between its opened and closed positions between a first condition permitting the locking element to reciprocate along the guide and a second condition bearing against the guide and canting the locking element into frictional engagement against the guide. The arrangement between the arm, the cam and the guide is an articulating cam lever that acts on the locking element in response to movement of the lever between its opened and closed positions.
The adjustment element is associated with the arm and the cam and is adjustable in reciprocal directions for adjusting the angular disposition of the cam relative to the guide for altering the clamping pressure applied by the jaws across a work piece in the closed position of the lever. The adjustment element is carried by one of the arm and the cam and is adjustable in reciprocal directions in opposition to the other of the arm and the cam. The adjustment element is movable in reciprocal directions in response to rotation thereof and a threaded attachment between the adjustment element and the one of the arm and the cam is well suited for this. The biasing element includes a spring captured between the locking element and at least one of the guide and the handle.